Cylinder rebuild

[Jyuma]

I'm rebuilding the lift cylinders but the Seal Kit for my cylinders contains several replacement seals that are quite different than the originals. I have been able to identify the proper installation orientation for most of them but the rod and the wiper seals are giving me some trouble. I'm assuming that if I knew the proper orientation for the wiper seal then the rod seal orientation would become obvious.
I've included 2 photo's below showing the wiper seal in position over the external face of the "Gland". My question is... which orientation is correct? A cross section of the wiper seal would show that there is a defined cone shape to the seal where it contacts the rod but I'm uncertain if the peak of the cone should face out (away from the cylinder) or in (toward the cylinder). Could someone please indicate which photo shows the correct orientation... One or Two.
One... This photo shows the "cone" facing in, toward the cylinder.

Two... this photo shows the "cone" facing out, away from the cylinder.

Note: I have not shown the "Rod Seal" which sits inside the Gland (you can see the grove for the "rod seal" inside the gland in the photo above) but I am assuming the "cone" of the rod seal would be opposite the cone of the wiper seal.
Maybe I'm making more out of this then there is... after all, both the rod seal and the wiper seal are required to seal in both directions so maybe it doesn't matter if the cone faces out or in so long as the two seals face in opposite directions???
Thanks

 

[Tazza]

I believe its seal b that is correct. Generally the writing faces out. The lips slide along the rod to keep the junk out.
The pressure seal should have its lips facing towards the pressure side (towards the piston). The oil creates pressure on the V like surface on the seal, the more hydraulic pressure there is, the harder its forced against the rod and gland.

 

[Jyuma]

I believe its seal b that is correct. Generally the writing faces out. The lips slide along the rod to keep the junk out.
The pressure seal should have its lips facing towards the pressure side (towards the piston). The oil creates pressure on the V like surface on the seal, the more hydraulic pressure there is, the harder its forced against the rod and gland.

Okay... I got the Gland reassembled and it looks good. Now I'm having a problem with the Piston.
The first photo shows the old piston assembly...

This next photo shows the new piston assembly...

Okay... now for the problem. There are two additional seals supplied with the new seal kit that didn't exist in the old seals.
Here is a photo of the two new seals that are included in the new seal kit. You would think they would have had enough common sense to include some instructions with the new seal kit especially if they were adding seals that didn't exist before.

Both seals have the same ID and OD but the seal on the left (in the photo) is about 3 times as thick. The thinner of the two is .040 and the thicker is .130 and looks like it has 2 edges that seal. In other words... if you took a cross section, the top would form a "V". Of particular interest is that the ID and OD are such that the two seals look like they could fit on the piston assembly between the piston halves and the plastic wear rings, but if that is where they are supposed to go I have no idea which would be the inner and which the outer.
Any ideas?

 

[Jyuma]

Okay... I got the Gland reassembled and it looks good. Now I'm having a problem with the Piston.
The first photo shows the old piston assembly...

This next photo shows the new piston assembly...

Okay... now for the problem. There are two additional seals supplied with the new seal kit that didn't exist in the old seals.
Here is a photo of the two new seals that are included in the new seal kit. You would think they would have had enough common sense to include some instructions with the new seal kit especially if they were adding seals that didn't exist before.

Both seals have the same ID and OD but the seal on the left (in the photo) is about 3 times as thick. The thinner of the two is .040 and the thicker is .130 and looks like it has 2 edges that seal. In other words... if you took a cross section, the top would form a "V". Of particular interest is that the ID and OD are such that the two seals look like they could fit on the piston assembly between the piston halves and the plastic wear rings, but if that is where they are supposed to go I have no idea which would be the inner and which the outer.
Any ideas?

I went ahead and put the piston and seals back together the same way they came apart... with the new seals of course. I assumed the seal kit covered a number of different cylinders and maybe the extra seals are used in the other cylinders. I know it's a guess, but that's all I've got.

The cylinder rebuild went good and the leak is gone. Now I need all new hoses.

Here's a picture of the beast up on it's trailer. They will both look a lot better after I paint them.

 

[Tazza]

I went ahead and put the piston and seals back together the same way they came apart... with the new seals of course. I assumed the seal kit covered a number of different cylinders and maybe the extra seals are used in the other cylinders. I know it's a guess, but that's all I've got.
The cylinder rebuild went good and the leak is gone. Now I need all new hoses.
Here's a picture of the beast up on it's trailer. They will both look a lot better after I paint them.

As you worked out, they must add them to allow for different cuts ont he piston between models.

 

[Jyuma]

As you worked out, they must add them to allow for different cuts ont he piston between models.

I see many people posting the total hours on their machines so out of curiosity I took a look at my Hobbs meter... it reads 1892.

 

[phk_xb]

I see many people posting the total hours on their machines so out of curiosity I took a look at my Hobbs meter... it reads 1892.

Where did you get the seal kit, was it OEM?
Evan.

 

[Jyuma]

Where did you get the seal kit, was it OEM?
Evan.

I got it from http://www.superiortrailerequipment.com/

 

[Jyuma]

I got it from http://www.superiortrailerequipment.com/

bTw... They needed the number stamped on the cylinder. For my cylinder the number 29877-87-01 was stamped on the bottom of the cylinder as it sits in the machine and toward the back. Yup... worst possible place to read it.

They didn't have my seal kit in stock... Seal Kit #023539SP... so they had it dropped shipped to me directly from Thomas in Canada. The shipping charges will make you weep... $33 bucks for a package (more like a letter) that weighed less than 1 lb.

 

[Tazza]

bTw... They needed the number stamped on the cylinder. For my cylinder the number 29877-87-01 was stamped on the bottom of the cylinder as it sits in the machine and toward the back. Yup... worst possible place to read it.
They didn't have my seal kit in stock... Seal Kit #023539SP... so they had it dropped shipped to me directly from Thomas in Canada. The shipping charges will make you weep... $33 bucks for a package (more like a letter) that weighed less than 1 lb.

That's why i deal with my local seal place, generally $25 does an entire cylinder.

 

[Jyuma]

That's why i deal with my local seal place, generally $25 does an entire cylinder.

lol... I thought of your prior post while I was typing my response.
Of course you are 100% correct but I haven't located a local seal place yet that would even return my call. I'm not giving up though... there is no way that I will continue to pay $33 to ship a $20.00 seal kit (that they charged me 50 bucks for).
The envelope that Thomas sent the seals in had a packing slip included and on that packing slip there was an entry at the bottom that read "Try Our On-Line Ordering System at www.thomas-equipment.com " I went there but it looks like you must be a distributor to use their On-Line ordering system. In the age of the Internet that just makes no sense.

 

[Tazza]

lol... I thought of your prior post while I was typing my response.
Of course you are 100% correct but I haven't located a local seal place yet that would even return my call. I'm not giving up though... there is no way that I will continue to pay $33 to ship a $20.00 seal kit (that they charged me 50 bucks for).
The envelope that Thomas sent the seals in had a packing slip included and on that packing slip there was an entry at the bottom that read "Try Our On-Line Ordering System at www.thomas-equipment.com " I went there but it looks like you must be a distributor to use their On-Line ordering system. In the age of the Internet that just makes no sense.

For seals, you need to take them to the shop. They won't have a clue about what seals are in say a 1990 743 bobcat. Thye need to see them and they can match them for you.
Don't give up! you will find a place.

 

[skidsteer.ca]

For seals, you need to take them to the shop. They won't have a clue about what seals are in say a 1990 743 bobcat. Thye need to see them and they can match them for you.
Don't give up! you will find a place.

Yes look for small equiment mechainc shops that are not brand specific, or hydraulic shops like hose assemblers and such. Packings get spendy as soon as a oem puts there name on the bag. My local guys here gets me better quality seals and for 30 % or oem. But he has to see them until I get better at learning whats in there.